US12122900B2 - Electromagnetic wave shielding molded article - Google Patents

Electromagnetic wave shielding molded article Download PDF

Info

Publication number
US12122900B2
US12122900B2 US16/760,089 US201816760089A US12122900B2 US 12122900 B2 US12122900 B2 US 12122900B2 US 201816760089 A US201816760089 A US 201816760089A US 12122900 B2 US12122900 B2 US 12122900B2
Authority
US
United States
Prior art keywords
molded article
electromagnetic wave
ghz
carbon fibers
wave shielding
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active, expires
Application number
US16/760,089
Other versions
US20210371623A1 (en
Inventor
Takafumi Ueda
Hirotomo Katano
Hiroshi Katayama
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Novacel Co Ltd
Original Assignee
Daicel Polymer Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=67993516&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=US12122900(B2) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Daicel Polymer Ltd filed Critical Daicel Polymer Ltd
Priority claimed from PCT/JP2018/040243 external-priority patent/WO2019088062A1/en
Assigned to DAICEL POLYMER LTD. reassignment DAICEL POLYMER LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: Katano, Hirotomo, UEDA, TAKAFUMI, KATAYAMA, HIROSHI
Publication of US20210371623A1 publication Critical patent/US20210371623A1/en
Assigned to Daicel Miraizu Ltd. reassignment Daicel Miraizu Ltd. CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: DAICEL FINECHEM LTD.
Assigned to DAICEL FINECHEM LTD. reassignment DAICEL FINECHEM LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: DAICEL POLYMER LTD.
Application granted granted Critical
Publication of US12122900B2 publication Critical patent/US12122900B2/en
Assigned to NOVACEL CO., LTD. reassignment NOVACEL CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: Daicel Miraizu Ltd.
Active legal-status Critical Current
Adjusted expiration legal-status Critical

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K7/00—Use of ingredients characterised by shape
    • C08K7/02—Fibres or whiskers
    • C08K7/04—Fibres or whiskers inorganic
    • C08K7/06—Elements
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
    • C08F110/00—Homopolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
    • C08F110/04—Monomers containing three or four carbon atoms
    • C08F110/06—Propene
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/02—Elements
    • C08K3/04—Carbon
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K9/00—Use of pretreated ingredients
    • C08K9/08—Ingredients agglomerated by treatment with a binding agent
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
    • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
    • C08L23/10—Homopolymers or copolymers of propene
    • C08L23/12—Polypropene
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q17/00—Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K9/00—Screening of apparatus or components against electric or magnetic fields
    • H05K9/0073—Shielding materials
    • H05K9/0081—Electromagnetic shielding materials, e.g. EMI, RFI shielding
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/002—Physical properties
    • C08K2201/004—Additives being defined by their length
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L2205/00—Polymer mixtures characterised by other features
    • C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
    • C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/27—Adaptation for use in or on movable bodies
    • H01Q1/32—Adaptation for use in or on road or rail vehicles
    • H01Q1/3208—Adaptation for use in or on road or rail vehicles characterised by the application wherein the antenna is used
    • H01Q1/3233—Adaptation for use in or on road or rail vehicles characterised by the application wherein the antenna is used particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems

Definitions

  • the present invention relates to an electromagnetic wave shielding and absorbing molded article having an advanced capability of shielding and absorbing electromagnetic waves having a specific wavelength.
  • a millimeter wave radar device used for the purpose of enabling automated driving and preventing collisions of automobiles is known.
  • a millimeter wave radar device is mounted to various locations such as the front center, both sides, and both rear sides of a vehicle, and is provided with: a high frequency module with an antenna for transmitting and receiving radio waves installed, a control circuit for controlling the radio waves, a housing that houses the antenna and the control circuit, and a radome covering the transmission and reception of radio waves for the antenna (JP 2007-74662 A).
  • a millimeter wave radar device thus constituted transmits and receives millimeter waves using the antenna, and can thereby detect relative distances and relative velocities with respect to an obstacle.
  • the antenna may also receive radio waves reflected from a road surface or other objects besides a target obstacle, and thus there is a risk that the detection accuracy of the device may be reduced.
  • the millimeter wave radar device according to JP 2007-74662 A is provided with a shielding member that shields radio waves between the antenna and the control circuit.
  • thermoplastic resin composition containing long carbon fibers with a fiber length of from 3 to 30 mm, and a molded article that is obtained therefrom and exhibits performance of shielding millimeter waves are proposed (JP 2015-7216 A).
  • an invention has been proposed with favorable electromagnetic wave shielding properties of a thermoplastic resin molded article containing carbon fibers having an average length of from 0.5 to 15 mm (JP 6123502 B).
  • An object of the present invention is to provide an electromagnetic wave shielding and absorbing molded article excelling in a shielding property and an absorbency for electromagnetic waves having a specific frequency.
  • the present invention provides an electromagnetic wave shielding and absorbing molded article including a thermoplastic resin composition that contains a thermoplastic resin and carbon fibers, the carbon fibers having a weighted average fiber length in the molded article in a range from 0.05 to 8.0 mm, and a content ratio of the carbon fibers in the molded article being from 0.05 to 45 mass %, where the electromagnetic wave shielding and absorbing molded article has a thickness from 0.01 mm to 5 mm, and a shielding property of 10 dB or greater and an absorbency of 5% or greater for electromagnetic waves having any frequency in a frequency domain from 59 GHz to 100 GHz.
  • the present invention also provides an electromagnetic wave shielding and absorbing molded article including a thermoplastic resin composition that contains a thermoplastic resin and carbon fibers, the carbon fibers having a weighted average fiber length in the molded article in a range from 0.05 to less than 1.05 mm, and a content ratio of the carbon fibers in the molded article being from 0.1 to 20 mass %, where the electromagnetic wave shielding and absorbing molded article has a thickness of from 0.01 mm to 5 mm, and a shielding property of 10 dB or greater and an absorbency of 25% or greater for electromagnetic waves having any frequency in a frequency domain from 59 GHz to 100 GHz.
  • the present invention also provides an electromagnetic wave shielding and absorbing molded article including a thermoplastic resin composition that contains a thermoplastic resin and carbon fibers, the carbon fibers having a weighted average fiber length in the molded article in a range from 1.05 to 8.0 mm, and a content ratio of the carbon fibers in the molded article being from 0.05 to 45 mass %, where the electromagnetic wave shielding and absorbing molded article has a thickness from 0.1 mm to 5 mm, and a shielding property of 30 dB or greater and an absorbency of 5% or greater for electromagnetic waves having any frequency in a frequency domain from 59 GHz to 100 GHz.
  • the electromagnetic wave shielding property according to the present invention exhibits a combined performance for both absorbency and reflectivity with respect to electromagnetic waves.
  • the electromagnetic wave shielding and absorbing molded article according to the present invention uses carbon fibers, which can increase both the shielding property and the absorbency for electromagnetic waves having a specific frequency. Furthermore, by using short carbon fibers and long carbon fibers, the electromagnetic wave shielding and absorbing molded article according to the present invention can increase both the shielding property and the absorbency for any electromagnetic waves having the frequency domain from 59 GHz to 100 GHz.
  • FIG. 1 is a schematic diagram of device that was used in the examples to measure the electromagnetic wave shielding property.
  • thermoplastic resin composition according to an embodiment of the present invention contains a predetermined amount of a combination of a thermoplastic resin and carbon fibers, and preferably uses a predetermined amount of short fibers or a predetermined amount of long fibers as the carbon fibers in order to obtain the combined performance of both a shielding property and an absorbency for electromagnetic waves.
  • thermoplastic resins selected from polypropylenes, propylene unit-containing copolymers and modified products of the copolymers (acid-modified products having a carboxyl group or a carbonyl group), styrene-based resins, polyphenylene sulfides, polyamides, polyethylene terephthalates, polybutylene terephthalates, and polycarbonates can be used, and the thermoplastic resin is preferably one or more selected from polypropylenes, and propylene unit-containing copolymers and modified products of the copolymers (acid-modified products having a carboxyl group or a carbonyl group), and is more preferably a polypropylene.
  • thermoplastic resin except for an acid-modified product having a carboxyl group or a carbonyl group
  • an acid-modified product having a carboxyl group or a carbonyl group such as maleic acid-modified polypropylene
  • the adhesion between the thermoplastic resin and the carbon fibers (short fibers or long fibers) in the molded article is improved, and thus such combined use is preferable.
  • the thermoplastic resin composition may be configured not containing an acid-modified product having a carboxyl group or a carbonyl group (such as maleic acid-modified polypropylene).
  • styrene-based resin a polystyrene or a copolymer containing a styrene unit (such as AS resin, ABS resin, ASA resin, AES resin, and MAS resin) can be used.
  • the weighted average fiber length in the electromagnetic wave shielding and absorbing molded article preferably ranges from 0.05 mm to less than 1.05 mm, and preferably ranges from 0.05 to 1.0 mm, and more preferably from 0.1 to 0.7 mm.
  • a content ratio of carbon fibers (short fibers) in the composition (the electromagnetic wave shielding and absorbing molded article) is from 0.1 to 20 mass %, and is preferably from 0.1 to 15 mass %.
  • the content ratio of carbon fibers (short fibers) in the composition (the electromagnetic wave shielding and absorbing molded article) is from 0.1 to 10 mass %, and preferably when the content ratio is from 0.1 to 5 mass %, the shielding property and the absorbency can be increased even when a thermoplastic resin (except for an acid-modified product having a carboxyl group or a carbonyl group) and an acid-modified product (such as a maleic acid-modified polypropylene) having a carboxyl group or a carbonyl group are not used in combination.
  • the ratio of carbon fibers having a fiber length of 0.5 mm or greater in the electromagnetic wave shielding and absorbing molded article is preferably 70 mass % or less.
  • a thermoplastic resin excluding an acid-modified product having a carboxyl group or a carbonyl group
  • an acid-modified product having a carboxyl group or a carbonyl group are not used in combination
  • the ratio of carbon fibers having a fiber length of 0.5 mm or longer in the electromagnetic wave shielding and absorbing molded article can also include a ratio exceeding 70 mass %.
  • the weighted average fiber length in the electromagnetic wave shielding and absorbing molded article preferably ranges from 1.05 to 8.0 mm, more preferably from 1.05 to 6.0 mm, even more preferably from 1.05 to 5.0 mm, and yet even more preferably from 1.05 to 4.0 mm.
  • Carbon fibers can be used in the form of long fiber pellets of resin-impregnated fiber bundles in which a thermoplastic resin is used.
  • a product obtained by impregnating and integrating a molten thermoplastic resin into carbon fibers in a bundled state with the carbon fibers aligned in the lengthwise direction can be cut to a length ranging from 2 to 30 mm, and preferably from 3 to 15 mm, and then used.
  • the method for producing the long fiber pellets of resin-impregnated fiber bundles in which a thermoplastic resin is used is a well-known method, and for example, those long fiber pellets can be produced using the methods described in JP 2013-107979 A (production of resin-impregnated long glass fiber bundles of Production Example 1), JP 2013-121988 A (production of resin-impregnated long glass fiber bundles of Production Example 1), JP 2012-52093 A (Examples 1 to 9), JP 2012-131104 A (production of resin-impregnated long glass fiber bundles of Production Example 1, production of long fiber bundles of resin-impregnated carbon fibers of Production Example 2), JP 2012-131918 A (production of resin-impregnated carbon fiber bundles of Production Example 1, production of resin-impregnated glass fiber bundles of Production Example 2), JP 2011-162905 A (Example 1), and JP 2004-14990 A (Examples 1 to 7).
  • the content ratio of carbon fibers (long fibers) in the composition (the electromagnetic wave shielding and absorbing molded article) is preferably from 0.05 to 45 mass %, more preferably from 0.1 to 45 mass %, even more preferably from 0.1 to 10 mass %, and yet even more preferably from 0.5 to 5 mass %.
  • an inorganic filler such as glass fibers or talc.
  • the content ratio of carbon fibers (long fibers) in the composition is from 0.1 to 10 mass %, and preferably when the content ratio is from 0.5 to 5 mass %, the shielding property and the absorbency can be increased even when a thermoplastic resin (except for an acid-modified product having a carboxyl group or a carbonyl group) and an acid-modified product (such as a maleic acid-modified polypropylene) having a carboxyl group or a carbonyl group are not used in combination.
  • the thermoplastic resin composition to be used in the present invention can contain a known resin additive within a range at which the problem of the present invention can be solved.
  • known resin additives include stabilizers against heat, light, UV light, and the like, lubricants, nucleating agents, plasticizers, known inorganic and organic fillers (excluding carbon fibers), antistatic agents, release agents, flame retardants, softeners, dispersants, antioxidants, and coloring materials.
  • the total content ratio of the abovementioned known resin additives in the composition (the electromagnetic wave shielding and absorbing molded article) is preferably 5 mass % or less, more preferably 3 mass % or less, even more preferably 1 mass % or less, and yet even more preferably 0.5 mass % or less.
  • the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention is obtained by molding the thermoplastic resin composition described above through application of a known resin molding method such as injection molding.
  • the size and shape of the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention can be appropriately adjusted, according to its application, within a range that satisfies the following thickness requirement.
  • the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention preferably has a thickness from 0.01 mm to 5 mm, more preferably from 0.05 mm to 5 mm, and even more preferably from 0.1 mm to 4 mm. The thickness is measured by a method described in the examples.
  • the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention preferably has a thickness from 0.1 mm to 5 mm, more preferably from 0.5 mm to 5 mm, and even more preferably from 0.5 mm to 4 mm. The thickness is measured by the method described in the examples.
  • the shielding property is preferably 10 dB or higher and the electromagnetic wave absorbency is preferably 25% or greater for electromagnetic waves having any frequency in a frequency domain from 59 GHz to 100 GHz.
  • both the electromagnetic wave shielding property and the electromagnetic wave absorbency for the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention preferably satisfy the electromagnetic wave shielding property and the electromagnetic wave absorbency described above for an entire frequency range from 75 GHz to 95 GHz, and more preferably for an entire frequency range from 59 GHz to 100 GHz.
  • the electromagnetic wave shielding property and the electromagnetic wave absorbency of the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention can be adjusted by adjusting a content ratio (R) and a thickness (T) of the carbon fibers.
  • R content ratio
  • T thickness
  • the weighted average fiber length of the carbon fibers remaining in the molded article preferably ranges from 0.1 to 1.0 mm.
  • the electromagnetic wave shielding and absorbing molded article has (R) ranging from 0.5 to 20 mass %, which is a content ratio of carbon fibers in the molded article, (T) ranging from 0.1 mm to 5 mm, which is a thickness of the molded article, and (R ⁇ T) ranging from 1.5 to 35, which is a product of (R) and (T),
  • the shielding property can be preferably set to 30 dB or greater and the absorbency can be preferably set to 25% or greater with respect to electromagnetic waves for any frequency in a frequency domain from 59 GHz to 100 GHz, or for an entire frequency domain from 75 GHz to 95 GHz.
  • the electromagnetic wave shielding and absorbing molded article has (R) ranging from 0.1 to 20 mass %, which is a content ratio of carbon fibers in the molded article, (T) ranging from 0.01 mm to 5 mm, which is a thickness of the molded article, and (R ⁇ T) ranging from 0.1 to 1.0, which is a product of (R) and (T),
  • the shielding property can be preferably set to 5 dB to less than 30 dB, and more preferably set to 10 dB to 25 dB and the absorbency can be can be set to preferably 40% or greater, more preferably 50% or greater, and even more preferably 60% or greater for electromagnetic waves having any frequency in the frequency domain from 59 GHz to 100 GHz.
  • the shielding property for electromagnetic waves having any frequency in a frequency domain from 59 GHz to 100 GHz can be preferably 30 dB or greater, more preferably to 40 dB or greater, even more preferably to 50 dB or greater, and yet even more preferably to 60 dB or greater.
  • the electromagnetic wave absorbency at any frequency in a frequency domain from 59 GHz to 100 GHz can be 5% or greater, preferably 7% or greater, and more preferably 10% or greater.
  • both the electromagnetic wave shielding property and the electromagnetic wave absorbency of the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention satisfy the electromagnetic wave shielding property and the electromagnetic wave absorbency described above, which is preferably for an entire frequency range from 75 GHz to 82 GHz, and more preferably for an entire frequency range from 70 GHz to 85 GHz.
  • the electromagnetic wave shielding property and the electromagnetic wave absorbency of the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention can be adjusted by adjusting the content ratio (R) and the thickness (T) of the carbon fibers.
  • the weighted average fiber length of the carbon fibers remaining in the molded article preferably ranges from 1.05 to 4.0 mm.
  • the electromagnetic wave shielding and absorbing molded article When long fibers are used for the carbon fibers, and the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention has a product (R ⁇ T) of the content ratio (R) of carbon fibers in the molded article (composition) and a thickness (T) of the molded article ranging preferably from 0.05 to 16, more preferably from 0.5 to less than 10, and preferably from 1 to 8, the electromagnetic wave shielding property in an entire range of frequencies from 70 GHz to 100 GHz can be 40 dB or greater, and the electromagnetic wave absorbency in the entire range thereof can be 10% or higher, and preferably 20% or higher.
  • the electromagnetic wave shielding and absorbing molded article When long fibers are used for the carbon fibers, and the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention has a range of a product (R ⁇ T) of the content ratio (R) of carbon fibers in the molded article (composition) and the thickness (T) of the molded article of greater than 16, and preferably from 18 to 100, the electromagnetic wave shielding property in the entire range of frequencies from 70 GHz to 100 GHz can be 70 dB or greater, and the electromagnetic wave absorbency can be 2% or greater.
  • the weighted average fiber length was determined from data obtained by measuring some of the extracted carbon fibers (500 fibers) using a LUZEX AP (available from Nireco Corporation). The calculation steps described in paragraphs [0044] and [0045] of JP 2006-274061 A were used to calculate the weighted average fiber length.
  • the ratio (quantity ratio) of carbon fibers of 0.5 mm or longer in the molded article was determined from the aforementioned method and is shown in Tables 1 and 2.
  • the thickness at a center portion (portion of intersection of diagonal lines) of a flat electromagnetic wave shielding and absorbing molded article (150 ⁇ 150 mm) was measured.
  • the tensile nominal strain was measured according to ISO527.
  • the measurement device illustrated in FIG. 1 was used.
  • a molded article 10 (length of 150 mm, width of 150 mm, thickness indicated in the table) to be measured was held between a pair of horizontally opposing antennas (corrugated horn antennas) 11 , 12 .
  • the spacing between the antenna 12 and the molded article 10 was 0 mm, and the spacing between the molded article 10 and the antenna 11 was 0 mm.
  • electromagnetic waves 65 to 110 GHz
  • electromagnetic waves transmitted through the molded article 10 to be measured were received by the upper antenna 11
  • the electromagnetic wave shielding property (the penetration inhibition of radiated waves) was calculated from equations 1 and 2 below
  • the electromagnetic wave absorbency was calculated from the equations 3 to 6 below.
  • the electromagnetic wave shielding property when electromagnetic waves (from 1 to 18 GHz) were emitted was also determined as follows using the measuring device illustrated in FIG. 1 .
  • the molded article 10 (length of 150 mm, width of 150 mm, thickness of 2 mm) to be measured was held between a pair of vertically facing antennas (wide band antennas; Schwarzbeck Mess-Elektronik, BBHA9120A, from 2 to 18 GHz) 11 , 12 .
  • the spacing between the antenna 12 and the molded article 10 was 85 mm, and the spacing between the molded article 10 and the antenna 11 was 10 mm.
  • Electromagnetic Wave Shielding Property (dB) 20 log(1/
  • S 21 (Transmitted Electric Field Intensity)/(Incident Electric Field Intensity) (Equation 2)
  • S 21 represents an S parameter (equation (2)) showing a ratio of a transmitted electric field intensity to an incident electric field intensity, and can be measured using a network analyzer 20 .
  • the logarithm of the reciprocal of the S parameter was used to express the electromagnetic wave shielding property (dB) as a positive value. With the measurement device of FIG. 1 , a range of from 0 to approximately 100 dB can be measured. Cases in which the electromagnetic wave shielding property exceeded 80 dB are indicated in the table by “>80 (dB)”, and cases in which the electromagnetic wave shielding property was less than 10 dB are indicated in the table by “10>(dB)”.
  • S 11 (Reflected Electric Field Intensity)/(Incident Electric Field Intensity) (Equation 3)
  • Equation 3 S 11 represent an S parameter showing a ratio of the reflected electric field intensity to the incident electric field intensity, and similar to S 21 , can be measured using the network analyzer.
  • PP polypropylene homopolymer, trade name “PM900A”, available from SunAllomer Ltd.
  • Acid-modified PP maleic anhydride modified polypropylene, trade name “OREVAC CA100”, maleic acid 1.0 mass % modification, available from Arkema K.K.
  • Prime Polypro 5119 (available from Prime Polymer Co., Ltd., homo PP)
  • Carbon fibers trade name “CFU-HC”, available from Nippon Polymer Sangyo Co., Ltd.
  • Sizing agent treated carbon fiber roving Pellets PP1 produced in Production Example 1 using Torayca T700SC-12000-50C (available from Toray Industries, Inc., treated with an epoxy sizing agent)
  • Stabilizer 1 phenol-based stabilizer, trade name “ADK STAB A0-60”, available from ADEKA Corporation
  • Stabilizer 2 sulfur-based stabilizer, trade name “TOWREX A0180T”, available from TOWREX
  • Lubricant calcium stearate, trade name “SC-PG”, available from Sakai Chemical Industry Co., Ltd.
  • the material was shaped with a shaping nozzle at the outlet of the crosshead die, and the shape was further refined with a shape refining roll, after which the sample was cut to a predetermined length using a pelletizer to obtain pellets (cylindrical molded articles) PP1 (containing 40 mass % of long carbon fibers) with a length of 8 mm.
  • the length of the long carbon fibers was the same as the pellet length.
  • the long carbon fibers were substantially parallel in the length direction.
  • the sizing agent treated carbon fiber roving was subjected to heating at 150° C. by a pre-heating device, and passed through a crosshead die. At that time, molten polypropylene (PP3 was used, acid-modified PP was not contained) was supplied to the crosshead die from a twin screw extruder, cylinder temperature: 280° C.), and the fiber bundles were impregnated with the polypropylene.
  • molten polypropylene PP3 was used, acid-modified PP was not contained
  • the material was shaped with a shaping nozzle at the outlet of the crosshead die, and the shape was further refined with a shape refining roll, after which the sample was cut to a predetermined length using a pelletizer to obtain pellets (cylindrical molded articles) PP4 (containing 40 mass % of long carbon fibers) with a length of 8 mm.
  • the length of the long carbon fibers was the same as the pellet length.
  • the long carbon fibers were substantially parallel in the length direction.
  • the components shown in Table 1 and Table 2 were dry blended, after which pellets (thermoplastic resin composition) were produced using an extruder (TEX30 ⁇ , Japan Steel Works, Ltd.). The obtained pellets were then used and molded using an injection molding machine ( ⁇ -150iA, available from Fanuc Corporation) at a molding temperature of 220° C. and a mold temperature of 50° C., and flat plate shaped electromagnetic wave shielding and absorbing molded articles (150 ⁇ 150 mm) according to an embodiment of the present invention were obtained. The obtained electromagnetic wave shielding and absorbing molded articles were used, and the various measurements shown in Tables 1 and 2 were performed.
  • the weighted average fiber length (weighted average value) of the carbon fibers in the molded article was short at 1 mm or less, but by associating the content ratio (R) and the thickness (T) of the carbon fibers and adjusting to the appropriate range, it was possible to obtain a high electromagnetic wave shielding property and electromagnetic wave absorbency in a wide frequency domain.
  • the ratio (quantity ratio) of carbon fibers of 0.5 mm or longer in the molded articles of Examples 7, 9, 11 and 12 was 50% or greater, and the quantity ratio for the other remaining examples was also 50% or greater.
  • Example 17 to 19 the content ratio of the carbon fibers was from 0.1 to 5.0 mass %, and an acid-modified PP was not used, but even compared to Examples 13 to 16 in which the same degree of carbon fibers was contained, Examples 17 to 19 exhibited comparable or higher shielding properties and absorbency.
  • Comparative Example 1 when the content amount of long carbon fibers was increased, a high electromagnetic wave shielding property was exhibited, but the electromagnetic wave absorbency was inferior to that of the examples. Moreover, Comparative Example 1 used 60-times or more the amount of carbon fibers compared to that of Example 1, and this high content amount is economically disadvantageous, and results in a large density, which is also disadvantageous in terms of weight reduction of the molded article. Comparative Example 2 did not contain carbon fibers, and as a result, did not provide any effect in shielding or absorbency.
  • Pellets of PP1 (pellets containing 40 mass % of the long carbon fibers obtained in Production Example 1; also containing acid-modified PP), PP2 (not containing carbon fibers), and PP4 (pellets containing 40 mass % of the long carbon fibers obtained in Production Example 2; not containing acid-modified PP) were dry blended at the ratios shown in Table 3, and molded at a molding temperature of 250° C. and a mold temperature of 50° C. using an injection molding machine ( ⁇ -150iA; available from Fanuc Corporation), and flat plate shaped electromagnetic wave shielding and absorbing molded articles (150 ⁇ 150 mm) were obtained. The obtained electromagnetic wave shielding and absorbing molded articles were used, and the various measurements shown in Table 3 were performed.
  • the weighted average fiber length (weighted average value) of the carbon fibers in the molded article was 1.05 mm or longer, and by associating the content ratio (R) and the thickness (T) of the carbon fibers and adjusting to the appropriate range, it was possible to adjust the electromagnetic wave shielding property and the electromagnetic wave absorbency in a wide frequency domain.
  • the content ratio of the carbon fibers was from 0.5 to 3 mass %, and an acid-modified PP was not used, but even compared to Examples 20 to 25 in which the same degree of carbon fibers was contained, Examples 32 and 33 exhibited comparable or higher shielding properties and absorbency.
  • the electromagnetic wave shielding and absorbing molded article of the present invention can be used for a millimeter wave radar device loaded in a vehicle for the purpose of enabling automated driving of the vehicle and preventing collisions, and for example, can be used in a shielding member (protective member for a transmitting and receiving antenna) that shields radio waves between the shielding member and a transmitting and receiving antenna control circuit for millimeter wave radar, in a housing for a millimeter wave radar device, and in a member for attaching a millimeter wave radar device, and can also be used in a housing for electrical and electronic equipment for a vehicle or for a device other than a vehicle.
  • a shielding member protecting member for a transmitting and receiving antenna
  • the electromagnetic wave shielding and absorbing molded article of the present invention can be used as a protective member for a wireless LAN or broadband wireless access system, a communication satellite, simple radio communications, an on-board radar, or a position recognition system, and more specifically, can be used as a protective member that shields radio waves of a base station antenna, a remote radio head (RRH; radio transceiver device), a baseband unit (BBU) device, a base GaN power amplifier, an optical transceiver, or the like.
  • RRH remote radio head
  • BBU baseband unit

Landscapes

  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Reinforced Plastic Materials (AREA)

Abstract

Provided is an electromagnetic wave shielding and absorbing molded article which has an excellent shielding property and absorbency of electromagnetic waves of specific frequencies. The electromagnetic wave shielding and absorbing molded article includes a thermoplastic resin composition containing a thermoplastic resin and carbon fibers. The carbon fibers have a weighted average fiber length in the molded article in a range from 0.05 to 8.0 mm, and the content ratio of the carbon fibers in the molded article is from 0.05 to 45 mass %. The electromagnetic wave shielding and absorbing molded article has a thickness from 0.01 mm to 5 mm, a shielding property of 10 dB or greater and an absorbency of 5% or greater for electromagnetic waves having any frequency in a frequency domain from 59 GHz to 100 GHz.

Description

TECHNICAL FIELD
The present invention relates to an electromagnetic wave shielding and absorbing molded article having an advanced capability of shielding and absorbing electromagnetic waves having a specific wavelength.
BACKGROUND ART
A millimeter wave radar device used for the purpose of enabling automated driving and preventing collisions of automobiles is known. A millimeter wave radar device is mounted to various locations such as the front center, both sides, and both rear sides of a vehicle, and is provided with: a high frequency module with an antenna for transmitting and receiving radio waves installed, a control circuit for controlling the radio waves, a housing that houses the antenna and the control circuit, and a radome covering the transmission and reception of radio waves for the antenna (JP 2007-74662 A). A millimeter wave radar device thus constituted transmits and receives millimeter waves using the antenna, and can thereby detect relative distances and relative velocities with respect to an obstacle. The antenna may also receive radio waves reflected from a road surface or other objects besides a target obstacle, and thus there is a risk that the detection accuracy of the device may be reduced. In order to solve this problem, the millimeter wave radar device according to JP 2007-74662 A is provided with a shielding member that shields radio waves between the antenna and the control circuit.
As an invention for solving the problems of the invention of JP 2007-74662 A, a thermoplastic resin composition containing long carbon fibers with a fiber length of from 3 to 30 mm, and a molded article that is obtained therefrom and exhibits performance of shielding millimeter waves are proposed (JP 2015-7216 A). In addition, an invention has been proposed with favorable electromagnetic wave shielding properties of a thermoplastic resin molded article containing carbon fibers having an average length of from 0.5 to 15 mm (JP 6123502 B).
SUMMARY OF INVENTION
An object of the present invention is to provide an electromagnetic wave shielding and absorbing molded article excelling in a shielding property and an absorbency for electromagnetic waves having a specific frequency.
The present invention provides an electromagnetic wave shielding and absorbing molded article including a thermoplastic resin composition that contains a thermoplastic resin and carbon fibers, the carbon fibers having a weighted average fiber length in the molded article in a range from 0.05 to 8.0 mm, and a content ratio of the carbon fibers in the molded article being from 0.05 to 45 mass %, where the electromagnetic wave shielding and absorbing molded article has a thickness from 0.01 mm to 5 mm, and a shielding property of 10 dB or greater and an absorbency of 5% or greater for electromagnetic waves having any frequency in a frequency domain from 59 GHz to 100 GHz.
The present invention also provides an electromagnetic wave shielding and absorbing molded article including a thermoplastic resin composition that contains a thermoplastic resin and carbon fibers, the carbon fibers having a weighted average fiber length in the molded article in a range from 0.05 to less than 1.05 mm, and a content ratio of the carbon fibers in the molded article being from 0.1 to 20 mass %, where the electromagnetic wave shielding and absorbing molded article has a thickness of from 0.01 mm to 5 mm, and a shielding property of 10 dB or greater and an absorbency of 25% or greater for electromagnetic waves having any frequency in a frequency domain from 59 GHz to 100 GHz.
The present invention also provides an electromagnetic wave shielding and absorbing molded article including a thermoplastic resin composition that contains a thermoplastic resin and carbon fibers, the carbon fibers having a weighted average fiber length in the molded article in a range from 1.05 to 8.0 mm, and a content ratio of the carbon fibers in the molded article being from 0.05 to 45 mass %, where the electromagnetic wave shielding and absorbing molded article has a thickness from 0.1 mm to 5 mm, and a shielding property of 30 dB or greater and an absorbency of 5% or greater for electromagnetic waves having any frequency in a frequency domain from 59 GHz to 100 GHz.
The electromagnetic wave shielding property according to the present invention exhibits a combined performance for both absorbency and reflectivity with respect to electromagnetic waves.
The electromagnetic wave shielding and absorbing molded article according to the present invention uses carbon fibers, which can increase both the shielding property and the absorbency for electromagnetic waves having a specific frequency. Furthermore, by using short carbon fibers and long carbon fibers, the electromagnetic wave shielding and absorbing molded article according to the present invention can increase both the shielding property and the absorbency for any electromagnetic waves having the frequency domain from 59 GHz to 100 GHz.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a schematic diagram of device that was used in the examples to measure the electromagnetic wave shielding property.
 DESCRIPTION OF EMBODIMENTS
<Thermoplastic Resin Composition>
A thermoplastic resin composition according to an embodiment of the present invention contains a predetermined amount of a combination of a thermoplastic resin and carbon fibers, and preferably uses a predetermined amount of short fibers or a predetermined amount of long fibers as the carbon fibers in order to obtain the combined performance of both a shielding property and an absorbency for electromagnetic waves.
One or more thermoplastic resins selected from polypropylenes, propylene unit-containing copolymers and modified products of the copolymers (acid-modified products having a carboxyl group or a carbonyl group), styrene-based resins, polyphenylene sulfides, polyamides, polyethylene terephthalates, polybutylene terephthalates, and polycarbonates can be used, and the thermoplastic resin is preferably one or more selected from polypropylenes, and propylene unit-containing copolymers and modified products of the copolymers (acid-modified products having a carboxyl group or a carbonyl group), and is more preferably a polypropylene.
When a thermoplastic resin (except for an acid-modified product having a carboxyl group or a carbonyl group) and an acid-modified product having a carboxyl group or a carbonyl group (such as maleic acid-modified polypropylene) are used in combination, the adhesion between the thermoplastic resin and the carbon fibers (short fibers or long fibers) in the molded article is improved, and thus such combined use is preferable. However, depending on the content amount of the carbon fibers, the thermoplastic resin composition may be configured not containing an acid-modified product having a carboxyl group or a carbonyl group (such as maleic acid-modified polypropylene).
As the styrene-based resin, a polystyrene or a copolymer containing a styrene unit (such as AS resin, ABS resin, ASA resin, AES resin, and MAS resin) can be used.
When short fibers are used for the carbon fibers, the weighted average fiber length in the electromagnetic wave shielding and absorbing molded article preferably ranges from 0.05 mm to less than 1.05 mm, and preferably ranges from 0.05 to 1.0 mm, and more preferably from 0.1 to 0.7 mm.
A content ratio of carbon fibers (short fibers) in the composition (the electromagnetic wave shielding and absorbing molded article) is from 0.1 to 20 mass %, and is preferably from 0.1 to 15 mass %. When the content ratio of carbon fibers (short fibers) in the composition (the electromagnetic wave shielding and absorbing molded article) is from 0.1 to 10 mass %, and preferably when the content ratio is from 0.1 to 5 mass %, the shielding property and the absorbency can be increased even when a thermoplastic resin (except for an acid-modified product having a carboxyl group or a carbonyl group) and an acid-modified product (such as a maleic acid-modified polypropylene) having a carboxyl group or a carbonyl group are not used in combination.
When short fibers are used for the carbon fibers, the ratio of carbon fibers having a fiber length of 0.5 mm or greater in the electromagnetic wave shielding and absorbing molded article is preferably 70 mass % or less. However, when a thermoplastic resin (excluding an acid-modified product having a carboxyl group or a carbonyl group) and an acid-modified product having a carboxyl group or a carbonyl group are not used in combination, the ratio of carbon fibers having a fiber length of 0.5 mm or longer in the electromagnetic wave shielding and absorbing molded article can also include a ratio exceeding 70 mass %.
When long fibers are used for the carbon fibers, the weighted average fiber length in the electromagnetic wave shielding and absorbing molded article preferably ranges from 1.05 to 8.0 mm, more preferably from 1.05 to 6.0 mm, even more preferably from 1.05 to 5.0 mm, and yet even more preferably from 1.05 to 4.0 mm.
Carbon fibers (long fibers) can be used in the form of long fiber pellets of resin-impregnated fiber bundles in which a thermoplastic resin is used. For the long fiber pellets of resin-impregnated fiber bundles, for example, a product obtained by impregnating and integrating a molten thermoplastic resin into carbon fibers in a bundled state with the carbon fibers aligned in the lengthwise direction, can be cut to a length ranging from 2 to 30 mm, and preferably from 3 to 15 mm, and then used. The method for producing the long fiber pellets of resin-impregnated fiber bundles in which a thermoplastic resin is used is a well-known method, and for example, those long fiber pellets can be produced using the methods described in JP 2013-107979 A (production of resin-impregnated long glass fiber bundles of Production Example 1), JP 2013-121988 A (production of resin-impregnated long glass fiber bundles of Production Example 1), JP 2012-52093 A (Examples 1 to 9), JP 2012-131104 A (production of resin-impregnated long glass fiber bundles of Production Example 1, production of long fiber bundles of resin-impregnated carbon fibers of Production Example 2), JP 2012-131918 A (production of resin-impregnated carbon fiber bundles of Production Example 1, production of resin-impregnated glass fiber bundles of Production Example 2), JP 2011-162905 A (Example 1), and JP 2004-14990 A (Examples 1 to 7).
The content ratio of carbon fibers (long fibers) in the composition (the electromagnetic wave shielding and absorbing molded article) is preferably from 0.05 to 45 mass %, more preferably from 0.1 to 45 mass %, even more preferably from 0.1 to 10 mass %, and yet even more preferably from 0.5 to 5 mass %. When the content amount of carbon fibers (long fibers) is small, the mechanical strength of the electromagnetic wave shielding and absorbing molded article can be increased by containing an inorganic filler (such as glass fibers or talc). Note that when the content ratio of carbon fibers (long fibers) in the composition (the electromagnetic wave shielding and absorbing molded article) is from 0.1 to 10 mass %, and preferably when the content ratio is from 0.5 to 5 mass %, the shielding property and the absorbency can be increased even when a thermoplastic resin (except for an acid-modified product having a carboxyl group or a carbonyl group) and an acid-modified product (such as a maleic acid-modified polypropylene) having a carboxyl group or a carbonyl group are not used in combination.
The thermoplastic resin composition to be used in the present invention can contain a known resin additive within a range at which the problem of the present invention can be solved. Examples of known resin additives include stabilizers against heat, light, UV light, and the like, lubricants, nucleating agents, plasticizers, known inorganic and organic fillers (excluding carbon fibers), antistatic agents, release agents, flame retardants, softeners, dispersants, antioxidants, and coloring materials. The total content ratio of the abovementioned known resin additives in the composition (the electromagnetic wave shielding and absorbing molded article) is preferably 5 mass % or less, more preferably 3 mass % or less, even more preferably 1 mass % or less, and yet even more preferably 0.5 mass % or less.
<Electromagnetic Wave Shielding and Absorbing Molded Article>
The electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention is obtained by molding the thermoplastic resin composition described above through application of a known resin molding method such as injection molding. The size and shape of the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention can be appropriately adjusted, according to its application, within a range that satisfies the following thickness requirement.
When short fibers are used for the carbon fibers, the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention preferably has a thickness from 0.01 mm to 5 mm, more preferably from 0.05 mm to 5 mm, and even more preferably from 0.1 mm to 4 mm. The thickness is measured by a method described in the examples.
When long fibers are used for the carbon fibers, the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention preferably has a thickness from 0.1 mm to 5 mm, more preferably from 0.5 mm to 5 mm, and even more preferably from 0.5 mm to 4 mm. The thickness is measured by the method described in the examples.
When short fibers are used for the carbon fibers, with the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention, the shielding property is preferably 10 dB or higher and the electromagnetic wave absorbency is preferably 25% or greater for electromagnetic waves having any frequency in a frequency domain from 59 GHz to 100 GHz. When short fibers are used for the carbon fibers, both the electromagnetic wave shielding property and the electromagnetic wave absorbency for the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention preferably satisfy the electromagnetic wave shielding property and the electromagnetic wave absorbency described above for an entire frequency range from 75 GHz to 95 GHz, and more preferably for an entire frequency range from 59 GHz to 100 GHz.
When short fibers are used for the carbon fibers, the electromagnetic wave shielding property and the electromagnetic wave absorbency of the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention can be adjusted by adjusting a content ratio (R) and a thickness (T) of the carbon fibers. Note that the weighted average fiber length of the carbon fibers remaining in the molded article preferably ranges from 0.1 to 1.0 mm.
When short fibers are used for the carbon fibers, and the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention has (R) ranging from 0.5 to 20 mass %, which is a content ratio of carbon fibers in the molded article, (T) ranging from 0.1 mm to 5 mm, which is a thickness of the molded article, and (R·T) ranging from 1.5 to 35, which is a product of (R) and (T), the shielding property can be preferably set to 30 dB or greater and the absorbency can be preferably set to 25% or greater with respect to electromagnetic waves for any frequency in a frequency domain from 59 GHz to 100 GHz, or for an entire frequency domain from 75 GHz to 95 GHz.
When short fibers are used for the carbon fibers, and the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention has (R) ranging from 0.1 to 20 mass %, which is a content ratio of carbon fibers in the molded article, (T) ranging from 0.01 mm to 5 mm, which is a thickness of the molded article, and (R·T) ranging from 0.1 to 1.0, which is a product of (R) and (T), the shielding property can be preferably set to 5 dB to less than 30 dB, and more preferably set to 10 dB to 25 dB and the absorbency can be can be set to preferably 40% or greater, more preferably 50% or greater, and even more preferably 60% or greater for electromagnetic waves having any frequency in the frequency domain from 59 GHz to 100 GHz.
When long fibers are used for the carbon fibers, with the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention, the shielding property for electromagnetic waves having any frequency in a frequency domain from 59 GHz to 100 GHz can be preferably 30 dB or greater, more preferably to 40 dB or greater, even more preferably to 50 dB or greater, and yet even more preferably to 60 dB or greater.
Furthermore, when long fibers are used for the carbon fibers, with the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention, the electromagnetic wave absorbency at any frequency in a frequency domain from 59 GHz to 100 GHz can be 5% or greater, preferably 7% or greater, and more preferably 10% or greater.
When long fibers are used for the carbon fibers, both the electromagnetic wave shielding property and the electromagnetic wave absorbency of the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention satisfy the electromagnetic wave shielding property and the electromagnetic wave absorbency described above, which is preferably for an entire frequency range from 75 GHz to 82 GHz, and more preferably for an entire frequency range from 70 GHz to 85 GHz.
When long fibers are used for the carbon fibers, the electromagnetic wave shielding property and the electromagnetic wave absorbency of the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention can be adjusted by adjusting the content ratio (R) and the thickness (T) of the carbon fibers. Note that the weighted average fiber length of the carbon fibers remaining in the molded article preferably ranges from 1.05 to 4.0 mm.
When long fibers are used for the carbon fibers, and the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention has a product (R·T) of the content ratio (R) of carbon fibers in the molded article (composition) and a thickness (T) of the molded article ranging preferably from 0.05 to 16, more preferably from 0.5 to less than 10, and preferably from 1 to 8, the electromagnetic wave shielding property in an entire range of frequencies from 70 GHz to 100 GHz can be 40 dB or greater, and the electromagnetic wave absorbency in the entire range thereof can be 10% or higher, and preferably 20% or higher.
When long fibers are used for the carbon fibers, and the electromagnetic wave shielding and absorbing molded article according to an embodiment of the present invention has a range of a product (R·T) of the content ratio (R) of carbon fibers in the molded article (composition) and the thickness (T) of the molded article of greater than 16, and preferably from 18 to 100, the electromagnetic wave shielding property in the entire range of frequencies from 70 GHz to 100 GHz can be 70 dB or greater, and the electromagnetic wave absorbency can be 2% or greater.
EXAMPLES
(1) Weighted Average Fiber Length
Approximately 3 g of a sample was cut out from a molded article, and the resin was fired to extract the carbon fibers. The weighted average fiber length was determined from data obtained by measuring some of the extracted carbon fibers (500 fibers) using a LUZEX AP (available from Nireco Corporation). The calculation steps described in paragraphs [0044] and [0045] of JP 2006-274061 A were used to calculate the weighted average fiber length. The ratio (quantity ratio) of carbon fibers of 0.5 mm or longer in the molded article was determined from the aforementioned method and is shown in Tables 1 and 2.
(2) Thickness (mm)
The thickness at a center portion (portion of intersection of diagonal lines) of a flat electromagnetic wave shielding and absorbing molded article (150×150 mm) was measured.
(3) Tensile Nominal Strain (%)
The tensile nominal strain was measured according to ISO527.
(4) Electromagnetic Wave Shielding Property and Electromagnetic Wave Absorbency
The measurement device illustrated in FIG. 1 was used. A molded article 10 (length of 150 mm, width of 150 mm, thickness indicated in the table) to be measured was held between a pair of horizontally opposing antennas (corrugated horn antennas) 11, 12. The spacing between the antenna 12 and the molded article 10 was 0 mm, and the spacing between the molded article 10 and the antenna 11 was 0 mm. In this state, electromagnetic waves (65 to 110 GHz) were radiated from the lower antenna 12, electromagnetic waves transmitted through the molded article 10 to be measured were received by the upper antenna 11, the electromagnetic wave shielding property (the penetration inhibition of radiated waves) was calculated from equations 1 and 2 below, and the electromagnetic wave absorbency was calculated from the equations 3 to 6 below. Furthermore, for the molded articles of Examples 2 and 7, the electromagnetic wave shielding property when electromagnetic waves (from 1 to 18 GHz) were emitted was also determined as follows using the measuring device illustrated in FIG. 1 . The molded article 10 (length of 150 mm, width of 150 mm, thickness of 2 mm) to be measured was held between a pair of vertically facing antennas (wide band antennas; Schwarzbeck Mess-Elektronik, BBHA9120A, from 2 to 18 GHz) 11, 12. The spacing between the antenna 12 and the molded article 10 was 85 mm, and the spacing between the molded article 10 and the antenna 11 was 10 mm. In this state, electromagnetic waves (from 1 to 18 GHz) were radiated from the lower antenna 12, electromagnetic waves transmitted through the molded article 10 to be measured were received by the upper antenna 11, and the electromagnetic wave shielding property (the penetration inhibition of radiated waves) was calculated from Equations 1 and 2 below.
Electromagnetic Wave Shielding Property (dB)=20 log(1/|s 21|)  (Equation 1)
S 21=(Transmitted Electric Field Intensity)/(Incident Electric Field Intensity)  (Equation 2)
In Equation 1, S21 represents an S parameter (equation (2)) showing a ratio of a transmitted electric field intensity to an incident electric field intensity, and can be measured using a network analyzer 20. In equation 1, the logarithm of the reciprocal of the S parameter was used to express the electromagnetic wave shielding property (dB) as a positive value. With the measurement device of FIG. 1 , a range of from 0 to approximately 100 dB can be measured. Cases in which the electromagnetic wave shielding property exceeded 80 dB are indicated in the table by “>80 (dB)”, and cases in which the electromagnetic wave shielding property was less than 10 dB are indicated in the table by “10>(dB)”.
S 11=(Reflected Electric Field Intensity)/(Incident Electric Field Intensity)  (Equation 3)
In Equation 3, S11 represent an S parameter showing a ratio of the reflected electric field intensity to the incident electric field intensity, and similar to S21, can be measured using the network analyzer. The absorptivity was denoted as a percentage as expressed by the following formula on a basis of power. The absorptivity is shown in the table as electromagnetic wave absorbency.
Transmittance (%)=S 21 2×100  (Equation 4)
Reflectance (%)=S 11 2×100  (Equation 5)
Absorptivity (%)=100−Transmittance−Reflectance  (Equation 6)
<Components Used>
(Thermoplastic Resin)
PP: polypropylene homopolymer, trade name “PM900A”, available from SunAllomer Ltd.
Acid-modified PP: maleic anhydride modified polypropylene, trade name “OREVAC CA100”, maleic acid 1.0 mass % modification, available from Arkema K.K.
PP2: SunAllomer PMB60A (block PP, available from SunAllomer Ltd.)
PP3: Prime Polypro 5119 (available from Prime Polymer Co., Ltd., homo PP)
(Carbon Fibers)
Carbon fibers: trade name “CFU-HC”, available from Nippon Polymer Sangyo Co., Ltd.
Sizing agent treated carbon fiber roving: Pellets PP1 produced in Production Example 1 using Torayca T700SC-12000-50C (available from Toray Industries, Inc., treated with an epoxy sizing agent)
(Other)
Stabilizer 1: phenol-based stabilizer, trade name “ADK STAB A0-60”, available from ADEKA Corporation
Stabilizer 2: sulfur-based stabilizer, trade name “TOWREX A0180T”, available from TOWREX
Lubricant: calcium stearate, trade name “SC-PG”, available from Sakai Chemical Industry Co., Ltd.
Production Example 1
The sizing agent treated carbon fiber roving was subjected to heating at 150° C. by a pre-heating device, and passed through a crosshead die. At that time, molten polypropylene (mixture of PP3: acid-modified PP=85:15 (mass ratio)) was supplied to the crosshead die from a twin screw extruder (cylinder temperature: 280° C.), and the fiber bundles were impregnated with the polypropylene. Next, the material was shaped with a shaping nozzle at the outlet of the crosshead die, and the shape was further refined with a shape refining roll, after which the sample was cut to a predetermined length using a pelletizer to obtain pellets (cylindrical molded articles) PP1 (containing 40 mass % of long carbon fibers) with a length of 8 mm. The length of the long carbon fibers was the same as the pellet length. In the pellets PP1 obtained in this manner, the long carbon fibers were substantially parallel in the length direction.
Production Example 2
The sizing agent treated carbon fiber roving was subjected to heating at 150° C. by a pre-heating device, and passed through a crosshead die. At that time, molten polypropylene (PP3 was used, acid-modified PP was not contained) was supplied to the crosshead die from a twin screw extruder, cylinder temperature: 280° C.), and the fiber bundles were impregnated with the polypropylene. Next, the material was shaped with a shaping nozzle at the outlet of the crosshead die, and the shape was further refined with a shape refining roll, after which the sample was cut to a predetermined length using a pelletizer to obtain pellets (cylindrical molded articles) PP4 (containing 40 mass % of long carbon fibers) with a length of 8 mm. The length of the long carbon fibers was the same as the pellet length. In the pellets PP4 obtained in this manner, the long carbon fibers were substantially parallel in the length direction.
Examples 1 to 19 and Comparative Examples 1 and 2
The components shown in Table 1 and Table 2 were dry blended, after which pellets (thermoplastic resin composition) were produced using an extruder (TEX30α, Japan Steel Works, Ltd.). The obtained pellets were then used and molded using an injection molding machine (α-150iA, available from Fanuc Corporation) at a molding temperature of 220° C. and a mold temperature of 50° C., and flat plate shaped electromagnetic wave shielding and absorbing molded articles (150×150 mm) according to an embodiment of the present invention were obtained. The obtained electromagnetic wave shielding and absorbing molded articles were used, and the various measurements shown in Tables 1 and 2 were performed.
TABLE 1
Examples
Units 1 2 3 4 5 6 7 8 9 10 11 12
Composition PP mass % 96.0   95.5 95.5 94.5 94.5 93.5 93.5 93.5 91.6 91.6 86.8 82.0
Acid-modified PP mass % 3.0   3.0 3.0 3.0 3.0 3.0 3.0 3.0 2.9 2.9 2.7 2.5
Stabilizer 1 mass % 0.2   0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2
Stabilizer 2 mass % 0.2   0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2
Lubricant mass % 0.1   0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1
Carbon fiber ratio (R) mass % 0.5  1 1 2 2 3 3 3 5 5 10 15
Total mass % 100
Molded Weighted Weighted mm 0.7   0.6 0.6 0.7 0.7 0.7 0.7 0.7 0.7 0.7 0.6 0.6
Article average fiber Average
length Ratio for 0.5 mm mass % 58 50 50 64 64 68 68 69 69 69 62 50
or greater
Thickness (T) mm 4  2 4 2 4 0.5 2 4 2 4 2 2
R · T — 2  2 4 4 8 1.5 6 12 10 20 20 30
Tensile nominal strain (4 mm % 8.9   7.8 7.8 6.4 6.4 6.1 6.1 6.1 4.8 4.8 1.8 1.0
thickness)
Shielding property (dB)  2 GHz  10> 17
10 GHz  10> 21
70 GHz 30 51 >80 77 >80 38 >80 >80 >80 >80 >80 >80
76 GHz 31 57 >80 79 >80 39 >80 >80 >80 >80 >80 >80
79 GHz 33 60 >80 80 >80 40 >80 >80 >80 >80 >80 >80
85 GHz 35 66 >80 >80 >80 43 >80 >80 >80 >80 >80 >80
95 GHz 39 >80  >80 >80 >80 48 >80 >80 >80 >80 >80 >80
100 GHz  40 >80  >80 >80 >80 48 >80 >80 >80 >80 >80 >80
Absorbency (%) 70 GHz 87.9 62 62 53 49 37 38 48 35 30 26 26
76 GHz 87.7 61 61 51 47 36 46 45 43 29 32 32
79 GHz 86.0 59 59 49 44 33 50 42 47 26 36 36
85 GHz 86.2 61 62 53 47 38 53 46 49 29 39 39
95 GHz 89.7 69 69 62 57 62 72 56 69 43 56 57
100 GHz  83.9 61 61 52 46 62 69 44 66 31 53 52
TABLE 2
Comparative
Examples Examples
Units 13 14 15 16 17 18 19 1 2
Composition PP mass % 96.4 96.4 93.5 91.6 99.4 98.5 94.5 67.4 96.3
Acid-modified PP mass % 3.0 3.0 3.0 2.9 — — — 2.1 3.0
Stabilizer 1 mass % 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.3
Stabilizer 2 mass % 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.2 0.3
Lubricant mass % 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1 0.1
Carbon fiber ratio (R) mass % 0.1 0.1 3 5 0.1 1.0 5.0 30 0
Total mass % 100 100
Molded Weighted Weighted mm 0.6 0.6 0.7 0.7 0.85 0.85 0.80 0.3 —
Article average fiber Average
length Ratio for 0.5 mm mass % 60 60 68 69 75 73 71 4 —
or greater
Thickness (T) mm 2 4 0.1 0.1 2 2 2 2 2
R · T — 0.2 0.4 0.3 0.5 0.2 2 10 60 0
Tensile nominal strain (4 mm % 14.9 14.9 6.1 4.8 18.0 10.0 5.0 0.7 15
thickness)
Shielding property (dB) 70 GHz 11 12 15 19 16 60 >80 >80 0
76 GHz 12 14 15 18 17 61 >80 >80 0
79 GHz 13 14 15 18 18 63 >80 >80 0
85 GHz 14 16 15 19 19 70 >80 >80 0
95 GHz 16 18 16 20 21 >80 >80 >80 0
100 GHz  16 18 16 20 21 >80 >80 >80 0
Absorbency (%) 70 GHz 86.1 88.6 62 54 83.0 59 33 24 0
76 GHz 88.4 87.0 58 48 85.0 59 41 29 0
79 GHz 88.6 85.9 55 46 87.0 57 45 36 0
85 GHz 90.4 88.9 54 48 88.0 59 46 40 0
95 GHz 93.5 96.1 61 55 91.0 66 66 60 0
100 GHz  90.5 94.9 55 48 90.0 59 65 57 0
In Examples 1 to 16, the weighted average fiber length (weighted average value) of the carbon fibers in the molded article was short at 1 mm or less, but by associating the content ratio (R) and the thickness (T) of the carbon fibers and adjusting to the appropriate range, it was possible to obtain a high electromagnetic wave shielding property and electromagnetic wave absorbency in a wide frequency domain. Note that the ratio (quantity ratio) of carbon fibers of 0.5 mm or longer in the molded articles of Examples 7, 9, 11 and 12 was 50% or greater, and the quantity ratio for the other remaining examples was also 50% or greater. In Examples 17 to 19, the content ratio of the carbon fibers was from 0.1 to 5.0 mass %, and an acid-modified PP was not used, but even compared to Examples 13 to 16 in which the same degree of carbon fibers was contained, Examples 17 to 19 exhibited comparable or higher shielding properties and absorbency. In Comparative Example 1, when the content amount of long carbon fibers was increased, a high electromagnetic wave shielding property was exhibited, but the electromagnetic wave absorbency was inferior to that of the examples. Moreover, Comparative Example 1 used 60-times or more the amount of carbon fibers compared to that of Example 1, and this high content amount is economically disadvantageous, and results in a large density, which is also disadvantageous in terms of weight reduction of the molded article. Comparative Example 2 did not contain carbon fibers, and as a result, did not provide any effect in shielding or absorbency.
Examples 20 to 33 and Comparative Example 3
Pellets of PP1 (pellets containing 40 mass % of the long carbon fibers obtained in Production Example 1; also containing acid-modified PP), PP2 (not containing carbon fibers), and PP4 (pellets containing 40 mass % of the long carbon fibers obtained in Production Example 2; not containing acid-modified PP) were dry blended at the ratios shown in Table 3, and molded at a molding temperature of 250° C. and a mold temperature of 50° C. using an injection molding machine (α-150iA; available from Fanuc Corporation), and flat plate shaped electromagnetic wave shielding and absorbing molded articles (150×150 mm) were obtained. The obtained electromagnetic wave shielding and absorbing molded articles were used, and the various measurements shown in Table 3 were performed.
TABLE 3
Examples
Units
20 21 22 23 24 25 28 27
Composition PPI mass % 1.3 1.3 2.5 7.5 7.5 7.5 12.5 25.0
PP2 mass % 98.7 98.7 97.5 92.5 92.5 92.5 87.5 75.0
PP4 mass % — — — — — — — —
Total mass % 100.0
Carbon fiber mass % 0.5 0.5 1 3 3 3 5 10
ratio (R)
Molded Thickness (T) mm 2 4 2 0.5 2 4 2 2
Article R · T — 1 2 2 1.5 6 12 10 20
Weighted average mm 3.14 3.14 2.79 2.63 2.63 2.63 2.42 2.93
fiber length
(weighted
average value)
Shielding  2 GHz 10> 11 19 23
property (dB) 10 GHz 10> 12 19 26
70 GHz 69 >80 >80 47 >80 >80 >80 >80
76 GHz 70 >80 >80 48 >80 >80 >80 >80
79 GHz 70 >80 >80 48 >80 >80 >80 >80
85 GHz 72 >80 >80 50 >80 >80 >80 >80
95 GHz 75 >80 >80 55 >80 >80 >80 >80
100 GHz  76 >80 >80 55 >80 >80 >80 >80
Absorbency (%) 70 GHz 52 51 43 30 29 27 25 7
76 GHz 51 49 41 29 23 21 19 8
79 GHz 49 47 38 25 20 17 14 9
85 GHz 53 51 43 31 26 23 22 10
95 GHz 63 60 55 60 37 34 32 4
100 GHz  55 53 43 58 21 15 10 3
Comparative
Examples Example
Units 28 29 30 31 32 33 3
Composition PPI mass % 50.0 50.0 75.0 100.0 — — —
PP2 mass % 50.0 50.0 25.0 0 98.7 92.5 100.0
PP4 mass % — — — — 1.3 7.5
Total mass % 100.0 100.0
Carbon fiber mass % 20 20 30 40 0.5 3 0
ratio (R)
Molded Thickness (T) mm 0.5 2 2 2 2 0.5 —
Article R · T — 10 40 60 80 1 1.5
Weighted average mm 2.05 2.35 1.70 1.05 3.30 2.73 —
fiber length
(weighted
average value)
Shielding  2 GHz 10>
property (dB) 10 GHz 10>
70 GHz >80 >80 >80 >80 72 51 0
76 GHz >80 >80 >80 >80 74 52 0
79 GHz >80 >80 >80 >80 74 52 0
85 GHz >80 >80 >80 >80 75 53 0
95 GHz >80 >80 >80 >80 78 58 0
100 GHz  >80 >80 >80 >80 79 56 0
Absorbency (%) 70 GHz 19 7 6 6 53 29 0
76 GHz 14 8 7 8 52 31 0
79 GHz 10 9 8 9 50 27 0
85 GHz 18 10 8 10 52 33 0
95 GHz 21 4 2 4 61 58 0
100 GHz  35 3 3 4 56 57 0
In Examples 20 to 31, the weighted average fiber length (weighted average value) of the carbon fibers in the molded article was 1.05 mm or longer, and by associating the content ratio (R) and the thickness (T) of the carbon fibers and adjusting to the appropriate range, it was possible to adjust the electromagnetic wave shielding property and the electromagnetic wave absorbency in a wide frequency domain. In Examples 32 and 33, the content ratio of the carbon fibers was from 0.5 to 3 mass %, and an acid-modified PP was not used, but even compared to Examples 20 to 25 in which the same degree of carbon fibers was contained, Examples 32 and 33 exhibited comparable or higher shielding properties and absorbency.
INDUSTRIAL APPLICABILITY
The electromagnetic wave shielding and absorbing molded article of the present invention can be used for a millimeter wave radar device loaded in a vehicle for the purpose of enabling automated driving of the vehicle and preventing collisions, and for example, can be used in a shielding member (protective member for a transmitting and receiving antenna) that shields radio waves between the shielding member and a transmitting and receiving antenna control circuit for millimeter wave radar, in a housing for a millimeter wave radar device, and in a member for attaching a millimeter wave radar device, and can also be used in a housing for electrical and electronic equipment for a vehicle or for a device other than a vehicle. Furthermore, the electromagnetic wave shielding and absorbing molded article of the present invention can be used as a protective member for a wireless LAN or broadband wireless access system, a communication satellite, simple radio communications, an on-board radar, or a position recognition system, and more specifically, can be used as a protective member that shields radio waves of a base station antenna, a remote radio head (RRH; radio transceiver device), a baseband unit (BBU) device, a base GaN power amplifier, an optical transceiver, or the like.

Claims (3)

The invention claimed is:
1. An electromagnetic wave shielding and absorbing molded article comprising a thermoplastic resin composition that includes a thermoplastic resin and carbon fibers, the carbon fibers having a weighted average fiber length in the molded article in a range from 0.6-0.7 mm, and a content of the carbon fibers in the molded article is from 0.5 to 15 mass %,
wherein the electromagnetic wave shielding and absorbing molded article has a thickness from 0.01 mm to 5 mm, and has a shielding property of 10 dB or greater and an absorbency of 5% or greater for electromagnetic waves having any frequency in a frequency domain from 59 GHz to 100 GHz,
wherein a content of the carbon fibers in the molded article having a fiber length of 0.5 mm or longer is 70 mass % or less, and
wherein the thermoplastic resin comprises a first thermoplastic resin that is acid-modified polypropylene and has a carboxyl group or a carbonyl group, and a second thermoplastic resin that is polypropylene,
wherein an amount of the acid-modified polypropylene is from 2.5 to 3.0 mass %, and
wherein an amount of the polypropylene is from 82.0 to 96.4 mass %.
2. The electromagnetic wave shielding and absorbing molded article according to claim 1, wherein the electromagnetic shielding and absorbing molded article is a protective member for a transmitting and receiving antenna.
3. The electromagnetic wave shielding and absorbing molded article according to claim 1, wherein a content ratio of carbon fibers in the molded article is set as R, a thickness of the molded article is set as T, and a range of (R·T) is 1.5-35.
US16/760,089 2017-10-30 2018-10-30 Electromagnetic wave shielding molded article Active 2039-12-29 US12122900B2 (en)

Applications Claiming Priority (11)

Application Number Priority Date Filing Date Title
JP2017209054 2017-10-30
JP2017-209054 2017-10-30
JP2017209052 2017-10-30
JP2017-209052 2017-10-30
JP2018-043080 2018-03-09
JP2018043082 2018-03-09
JP2018-043082 2018-03-09
JP2018043080 2018-03-09
JP2018-194175 2018-10-15
JP2018194175A JP7249478B2 (en) 2017-10-30 2018-10-15 Electromagnetic wave shielding molding
PCT/JP2018/040243 WO2019088062A1 (en) 2017-10-30 2018-10-30 Electromagnetic wave shielding molded article

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2018/040243 A-371-Of-International WO2019088062A1 (en) 2017-10-30 2018-10-30 Electromagnetic wave shielding molded article

Related Child Applications (2)

Application Number Title Priority Date Filing Date
US18/894,440 Division US20250011578A1 (en) 2017-10-30 2024-09-24 Electromagnetic wave shielding molded article
US18/894,467 Division US20250011579A1 (en) 2017-10-30 2024-09-24 Electromagnetic wave shielding molded article

Publications (2)

Publication Number Publication Date
US20210371623A1 US20210371623A1 (en) 2021-12-02
US12122900B2 true US12122900B2 (en) 2024-10-22

Family

ID=67993516

Family Applications (1)

Application Number Title Priority Date Filing Date
US16/760,089 Active 2039-12-29 US12122900B2 (en) 2017-10-30 2018-10-30 Electromagnetic wave shielding molded article

Country Status (5)

Country Link
US (1) US12122900B2 (en)
EP (1) EP3706527A4 (en)
JP (1) JP7249478B2 (en)
CN (1) CN111279808B (en)
TW (1) TWI827558B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220403125A1 (en) * 2019-11-25 2022-12-22 Toray Industries, Inc. Fiber-reinforced thermoplastic resin molded article

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2019135137A1 (en) 2018-01-05 2019-07-11 株式会社半導体エネルギー研究所 Semiconductor device and production method for semiconductor device
JP7269788B2 (en) * 2019-04-26 2023-05-09 東レプラスチック精工株式会社 Thermoplastic resin carbon fiber composite material and shielding material for shielding millimeter waves
JP7606694B2 (en) * 2019-10-02 2024-12-26 三恵技研工業株式会社 Electromagnetic wave absorbing material and electromagnetic wave absorbing resin molding
MX2022016392A (en) * 2020-06-17 2023-01-30 Mitsubishi Eng Plastics Corp Resin composition, molded body, electromagnetic wave absorber, and method for measuring absorption rate of resin composition.
EP4023709A1 (en) * 2020-12-31 2022-07-06 SHPP Global Technologies B.V. Pbt-carbon fiber composites for microwave shielding
US20230250276A1 (en) * 2021-02-25 2023-08-10 Mitsubishi Engineering-Plastics Corporation Resin composition, formed article, electromagnetic wave absorber, and, method for producing resin composition
JP6927448B1 (en) * 2021-04-27 2021-09-01 東洋インキＳｃホールディングス株式会社 Thermoplastic resin composition and molded product for electromagnetic wave absorber
WO2023218940A1 (en) * 2022-05-12 2023-11-16 出光興産株式会社 Radio wave absorber, radio wave absorbing structure including radio wave absorber, and composition for radio wave absorber

Citations (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2000013090A (en) 1998-06-23 2000-01-14 Jamco Corp gasket
US6051307A (en) * 1999-01-30 2000-04-18 Asahi Kasei Kogyo Kabushiki Kaisha Thermoplastic molded article containing carbon fiber
US6202883B1 (en) * 1998-02-06 2001-03-20 Mitsubishi Engineering-Plastics Corp. Tray for semiconductor integrated circuit devices
JP2004014990A (en) 2002-06-11 2004-01-15 Daicel Chem Ind Ltd Resin composition for electromagnetic wave shielding
JP2006274061A (en) 2005-03-29 2006-10-12 Kuraray Co Ltd Long fiber reinforced semi-aromatic polyamide resin composition
JP2007074662A (en) 2005-09-09 2007-03-22 Hitachi Ltd Millimeter wave radar equipment
US20080071024A1 (en) * 2004-07-15 2008-03-20 Takuya Morishita Thermoplastic Resin Composition
JP2011162905A (en) 2010-02-09 2011-08-25 Daicel Polymer Ltd Fiber material for reinforcing molding material
JP2012052093A (en) 2010-08-03 2012-03-15 Daicel Polymer Ltd Thin-walled molded form for electronic equipment housing
JP2012131918A (en) 2010-12-22 2012-07-12 Daicel Polymer Ltd Resin composition for abrasion-resistant molding
JP2012131104A (en) 2010-12-21 2012-07-12 Daicel Polymer Ltd Molding for preventing electric leakage and electric shock
JP2012158648A (en) 2011-01-31 2012-08-23 Japan Polypropylene Corp Propylene-based resin composition for electromagnetic shielding, method for producing the same, and molded article
JP2013107979A (en) 2011-11-21 2013-06-06 Daicel Polymer Ltd Resin composition
JP2013121988A (en) 2011-05-16 2013-06-20 Daicel Polymer Ltd Flame-retardant resin composition
JP2015007216A (en) 2013-05-30 2015-01-15 ダイセルポリマー株式会社 Thermoplastic resin composition for molded article having millimeter wave shielding performance
US20150315371A1 (en) * 2012-11-30 2015-11-05 Mitsubishi Rayon Co., Ltd. Pellet mixture, carbon fiber-reinforced polypropylene resin composition, molded body, and method for producing pellet mixture
US20160122513A1 (en) * 2013-06-07 2016-05-05 Mazda Motor Corporation Thermoplastic resin moulded article, and production method for thermoplastic resin moulded article
JP6123502B2 (en) 2013-06-07 2017-05-10 マツダ株式会社 Thermoplastic resin molded article and method for producing thermoplastic resin molded article
US20200010588A1 (en) * 2017-02-28 2020-01-09 Mitsui Chemicals, Inc. Electroconductive resin composition, method for manufacturing same and molded article obtained therefrom

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4529206B2 (en) * 1998-11-30 2010-08-25 東レ株式会社 Fiber reinforced resin composition and molded article
JP2014062189A (en) * 2012-09-21 2014-04-10 Mitsubishi Motors Corp Battery case for vehicle

Patent Citations (21)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6202883B1 (en) * 1998-02-06 2001-03-20 Mitsubishi Engineering-Plastics Corp. Tray for semiconductor integrated circuit devices
JP2000013090A (en) 1998-06-23 2000-01-14 Jamco Corp gasket
US6051307A (en) * 1999-01-30 2000-04-18 Asahi Kasei Kogyo Kabushiki Kaisha Thermoplastic molded article containing carbon fiber
JP2004014990A (en) 2002-06-11 2004-01-15 Daicel Chem Ind Ltd Resin composition for electromagnetic wave shielding
US20080071024A1 (en) * 2004-07-15 2008-03-20 Takuya Morishita Thermoplastic Resin Composition
JP2006274061A (en) 2005-03-29 2006-10-12 Kuraray Co Ltd Long fiber reinforced semi-aromatic polyamide resin composition
JP2007074662A (en) 2005-09-09 2007-03-22 Hitachi Ltd Millimeter wave radar equipment
JP2011162905A (en) 2010-02-09 2011-08-25 Daicel Polymer Ltd Fiber material for reinforcing molding material
JP2012052093A (en) 2010-08-03 2012-03-15 Daicel Polymer Ltd Thin-walled molded form for electronic equipment housing
JP2012131104A (en) 2010-12-21 2012-07-12 Daicel Polymer Ltd Molding for preventing electric leakage and electric shock
JP2012131918A (en) 2010-12-22 2012-07-12 Daicel Polymer Ltd Resin composition for abrasion-resistant molding
JP2012158648A (en) 2011-01-31 2012-08-23 Japan Polypropylene Corp Propylene-based resin composition for electromagnetic shielding, method for producing the same, and molded article
JP2013121988A (en) 2011-05-16 2013-06-20 Daicel Polymer Ltd Flame-retardant resin composition
JP2013107979A (en) 2011-11-21 2013-06-06 Daicel Polymer Ltd Resin composition
US20150315371A1 (en) * 2012-11-30 2015-11-05 Mitsubishi Rayon Co., Ltd. Pellet mixture, carbon fiber-reinforced polypropylene resin composition, molded body, and method for producing pellet mixture
JP2015007216A (en) 2013-05-30 2015-01-15 ダイセルポリマー株式会社 Thermoplastic resin composition for molded article having millimeter wave shielding performance
EP3006510A1 (en) 2013-05-30 2016-04-13 Daicel Polymer Ltd. Thermoplastic resin composition for moulded article exhibiting millimetre-wave shielding ability
US20160111792A1 (en) 2013-05-30 2016-04-21 Daicel Polymer Ltd. Thermoplastic resin composition for molded article having capability of shielding millimeter waves
US20160122513A1 (en) * 2013-06-07 2016-05-05 Mazda Motor Corporation Thermoplastic resin moulded article, and production method for thermoplastic resin moulded article
JP6123502B2 (en) 2013-06-07 2017-05-10 マツダ株式会社 Thermoplastic resin molded article and method for producing thermoplastic resin molded article
US20200010588A1 (en) * 2017-02-28 2020-01-09 Mitsui Chemicals, Inc. Electroconductive resin composition, method for manufacturing same and molded article obtained therefrom

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
English translation of International Preliminary Report on Patentability and Written Opinion mailed May 14, 2020, in PCT/JP2018/040243 (Forms PCT/IB/338, PCT/IB/373, and PCT/ISA/237).
Extended European Search Report issued Jul. 16, 2021, in European Patent Application No. 18874925.3.

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220403125A1 (en) * 2019-11-25 2022-12-22 Toray Industries, Inc. Fiber-reinforced thermoplastic resin molded article

Also Published As

Publication number Publication date
US20210371623A1 (en) 2021-12-02
EP3706527A1 (en) 2020-09-09
JP2019161208A (en) 2019-09-19
TW201925313A (en) 2019-07-01
TWI827558B (en) 2024-01-01
EP3706527A4 (en) 2021-08-18
CN111279808A (en) 2020-06-12
JP7249478B2 (en) 2023-03-31
CN111279808B (en) 2023-03-31

Similar Documents

Publication Publication Date Title
US12122900B2 (en) Electromagnetic wave shielding molded article
US20250011579A1 (en) Electromagnetic wave shielding molded article
KR102243852B1 (en) Thermoplastic resin composition for moulded article exhibiting millimetre-wave shielding ability
CN115413285B (en) Thermoplastic resins for network applications
JP7306813B2 (en) Electromagnetic wave shielding molding
US11515644B2 (en) Electromagnetic wave shielding and absorbing molded article
CN105246967B (en) Thermoplastic resin molded article and method for producing thermoplastic resin molded article
TWI783071B (en) Electromagnetic wave shielding absorbent molded article
JP7249481B2 (en) Electromagnetic wave shielding and absorbing molded body
JP6155862B2 (en) Thermoplastic resin molded article and method for producing thermoplastic resin molded article
JP6777710B2 (en) Radar transmit / receive antenna protection
CN116648477A (en) Fiber reinforced propylene polymer composition
CN118234786A (en) Polycarbonate compositions containing carbon nanotubes (CNTS) as microwave absorbers in automotive radar sensor applications
TW202229455A (en) Thermoplastic resins for network applications

Legal Events

Date Code Title Description
AS Assignment

Owner name: DAICEL POLYMER LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:UEDA, TAKAFUMI;KATANO, HIROTOMO;KATAYAMA, HIROSHI;SIGNING DATES FROM 20200227 TO 20200228;REEL/FRAME:052527/0898

FEPP Fee payment procedure

Free format text: ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: FINAL REJECTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: FINAL REJECTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: ADVISORY ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

STPP Information on status: patent application and granting procedure in general

Free format text: NOTICE OF ALLOWANCE MAILED -- APPLICATION RECEIVED IN OFFICE OF PUBLICATIONS

ZAAA Notice of allowance and fees due

Free format text: ORIGINAL CODE: NOA

ZAAB Notice of allowance mailed

Free format text: ORIGINAL CODE: MN/=.

STPP Information on status: patent application and granting procedure in general

Free format text: PUBLICATIONS -- ISSUE FEE PAYMENT RECEIVED

STPP Information on status: patent application and granting procedure in general

Free format text: PUBLICATIONS -- ISSUE FEE PAYMENT VERIFIED

AS Assignment

Owner name: DAICEL MIRAIZU LTD., JAPAN

Free format text: CHANGE OF NAME;ASSIGNOR:DAICEL FINECHEM LTD.;REEL/FRAME:068986/0226

Effective date: 20200706

Owner name: DAICEL FINECHEM LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:DAICEL POLYMER LTD.;REEL/FRAME:068625/0022

Effective date: 20200701

STCF Information on status: patent grant

Free format text: PATENTED CASE

AS Assignment

Owner name: NOVACEL CO., LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:DAICEL MIRAIZU LTD.;REEL/FRAME:069077/0140

Effective date: 20241008